Cutting tool and cutting insert with fluid flow structures

ABSTRACT

A cutting tool includes a cutting insert comprising a top surface, a bottom surface, a clamping surface for abutting a clamp, a cutting edge, a hole extending through the insert from the bottom surface to the clamping surface, and a channel extending from the clamping surface to proximate the cutting edge, and a tool holder comprising a tool holder body having a pocket for receiving the insert, a clamp for contacting the clamping surface and clamping the insert in the pocket, and a tool holder passage in the body in flow communication with the hole in the insert. A cutting insert is also provided.

BACKGROUND AND SUMMARY

The present invention relates generally to cutting tools and cuttinginserts and, more particularly, to such cutting tools and inserts havingfluid flow channels.

Conventional techniques for providing lubricating and/or cooling fluidto cutting edges of cutting inserts typically involve introducing thefluid via openings in a toolholder for the cutting insert, or via spraynozzles directed at the cutting edges. Some cutting inserts includechannels formed in the inserts that are in flow communication with andfacilitate introduction of fluid from channels provided in thetoolholder body. The provision of these fluid flow channels in thecutting inserts tends to substantially complicate manufacture of theinserts, and the channels can weaken the insert. It is desirable toprovide a cutting tool and cutting insert that facilitate introductionof fluid to the cutting edges of the insert that minimizes manufacturingcomplexity. It is also desirable to provide a cutting tool and cuttinginsert that facilitate introduction of fluid to the cutting edge withoutsubstantially interfering with the strength of the insert.

According to an aspect of the present invention, a cutting insertcomprises a top surface, a bottom surface, a clamping surface forabutting a clamp, a cutting edge, a hole extending through the insertfrom the bottom surface to the clamping surface, and a channel extendingfrom the clamping surface to point proximate and inward of the cuttingedge.

According to an aspect of the present invention, a cutting toolcomprises a cutting insert comprising a top surface, a bottom surface, aclamping surface, a cutting edge, a hole extending through the insertfrom the bottom surface to the clamping surface, and a channel extendingfrom the clamping surface to proximate the cutting edge, and atoolholder comprising a toolholder body having a pocket for receivingthe insert, a clamp for contacting the clamping surface and clamping theinsert in the pocket, and a toolholder passage in the body in flowcommunication with the hole in the insert.

BRIEF DESCRIPTION OF THE DRAWINGS

The features and advantages of the present invention are well understoodby reading the following detailed description in conjunction with thedrawings in which like numerals indicate similar elements and in which:

FIG. 1A is a side, cross-sectional view of a portion of a cutting toolaccording to an aspect of the present invention, and FIG. 1B is a sideview and FIG. 1C is a top view of components of a cutting tool accordingto an aspect of the present invention; and

FIG. 2A is a top view, FIG. 2B is a side view, FIG. 2C is a side,cross-sectional view, and FIG. 2D is a side, partially cross-sectionalview of an insert according to an aspect of the present invention.

DETAILED DESCRIPTION

An illustrative cutting tool 21 according to an aspect of the presentinvention is shown in FIG. 1A. The cutting tool 21 comprises a cuttinginsert 23 comprising a top surface 25 and a bottom surface 27. Theinsert 23 also comprises a clamping surface 29 for abutting a clamp 31and a cutting edge 33. A hole 35 extends through the insert 23 from thebottom surface 27 to the clamping surface 29. A channel 37 extends fromthe clamping surface 29 to point proximate and inward of the cuttingedge 33.

The cutting tool 21 also comprises a toolholder 39 comprising atoolholder body 41 having a pocket 43 for receiving the insert 23. Thetoolholder 39 also comprises the clamp 31 for contacting the clampingsurface 29 and clamping the insert in the pocket 43. The toolholder 39also comprises a toolholder passage 45 in the body 41 in flowcommunication with the hole 35 in the insert 23. By providing thecutting tool 21 and cutting insert 23 with a fluid flow passage Pextending from the toolholder passage 45 through a hole 35 extendingthrough the insert from the bottom surface 27 to the clamping surface29, and a channel 37 extending from the clamping surface to proximatethe cutting edge 33, introduction of fluid to the cutting edges of theinsert can be achieved in a manner that minimizes manufacturingcomplexity and that does not substantially interfere with the strengthof the insert, as many insert types are already manufactured with holesfor clamping members extending through them.

In the cutting tool 21 and components of the cutting tool illustrated inFIG. 1A-1C, the clamp 31 can comprise a clamping arm 47 having an armclamping surface 49 for contacting the clamping surface 29. Where, as inthe insert 23 shown in FIG. 1A, the clamping surface 29 is in the formof a truncated cone, the rear end 51 of the arm clamping surface 49 willordinarily be rounded, such as partially spherical or in the form of acone or a truncated cone, so that there will be substantially linecontact between the clamping surface 29 and the arm clamping surface 49.

As with conventional arm clamping-type clamps, when a bolt 53 securingthe clamping arm 47 to the body 41 of the toolholder 39 is tightened,the arm will tend to pivot and the arm clamping surface 49 will tend tourge the insert 23 toward the bolt 53 and into a corner 55 of the pocket43. As seen in FIG. 1C, ordinarily, at least two side insert supportingpoints or areas 57 a and 57 b on the edge surface 59 of the insert 23will contact corresponding abutment points or areas 61 a and 61 b (shownin phantom) on side surfaces 63 of the pocket. A forward portion 65 ofthe clamping arm 47 can include a recess 67 so that, when the rear end51 of the arm clamping surface 49 contacts the clamping surface 29 ofthe insert 23, the clamping arm will not prevent flow communicationbetween the hole 35 and the channel 37.

Instead of a clamp having a clamping arm, the clamp can take othersuitable forms such as a bolt having a clamping surface that extendsthrough a hole in the insert and mates with a threaded opening in thetoolholder. The bolt can have a passage for permitting fluid flowthrough the hole to the channel. A deflecting surface for deflectingfluid into the channel can be provided on the bolt, e.g., at the top ofa passage in the bolt below a head of the bolt, or can be providedseparately, such as on the toolholder or a separate member that may besecured, e.g., by the bolt.

As seen in FIGS. 1A and 1B, the toolholder 39 can comprise a shim 69disposed in the pocket 43. As seen in FIG. 1A, the toolholder passage 45extends at least in part through the shim 69. A fitting 71 can extendthrough a hole 73 in the shim 69 and into an opening 75 in thetoolholder body 41. The fitting 71 can be a bolt, and the opening 75 canbe a threaded opening for mating with the bolt, however, FIG. 1A shows afitting that merely extends through the hole 73 in the shim into anopening and includes an open end 77 that is in flow communication with asource S of fluid, such as by connecting the end to a fitting on a hoseconnected to a reservoir of cooling and/or lubricating fluid (e.g.,liquid, air, etc.) or by connecting a fitting on a hose to an opening 81on the body of the toolholder that forms part of the toolholder passage45. The toolholder passage 45 can extend at least in part through thehole 73 in the shim 69 and can extend at least in part through thefitting 71. The fitting 71 can include an enlarged end 79 that isprevented from passing entirely through the hole 73 in the shim 69.

As seen in FIGS. 2A and 2C, the hole 35 in the insert 23 comprises afirst portion 83 having a substantially constant diameter along itslength and a second portion 85 that has a diameter that changes over atleast part of its length. Ordinarily, the second portion 85 of the hole35 is a frustoconical portion defining an angle • (FIG. 2D showing anangle of 45°) with an axis of the hole 35 or a substantiallyfrustoconical portion. The second portion 85 can comprise at least partof the clamping surface 29 and ordinarily the clamping surface comprisesa substantially smooth surface interrupted by the channel 37. By“smooth” is here meant a surface like a directly pressed surface thatdoes not exhibit a high surface roughness or irregularities. The firstportion 83 of the hole 35 can form at least part of the clamping surface29, as well. As seen in FIG. 1A, the rear end 51 of the arm clampingsurface 49 includes a first portion 87 that is intended to abut thefirst portion 83 of the hole 35 of the insert, and a frustoconicalportion 89 that is intended to abut the second portion 85 of the hole.By providing the recess 67 at the forward portion 65 of the arm clampingsurface 49, positioning of the recess so that it does not block thechannel 37 can be ensured.

As seen in FIG. 2C, the channel 37 can be radiused with radius R and adepth of the channel is ordinarily greater at a first end 91 of thechannel at the clamping surface 29 than at a second end 93 proximate andinward of the cutting edge 33. The depth of the channel 37 at the firstend 91 of the channel can be greater than a depth of the second portion85 of the hole 35. In the insert 23 shown in FIG. 1, the depth of thechannel 37 decreases toward the cutting edge so that the second end 93of the channel merges into the top surface 25 before the cutting edge33. The top surface 25 comprises a strengthening geometry or landsurface 95 between the cutting edge 33 and the second end 93 of thechannel 37. Chipbreakers 97 can be provided on opposite sides of thechannel 37.

In an insert 23 comprising at least two cutting edges 33 as seen in,e.g., FIGS. 2A-2C, at least two channels 37 (seen in FIGS. 2A and 2C)can be provided, and at least one channel of the at least two channelscan extend from the clamping surface 29 to proximate and inward of arespective one of the cutting edges 33. Some or all of the channels 37can be disposed under the arm clamping surface 49, as seen in FIG. 1A.Additional channels can be provided proximate each cutting edge ifdesired. In an insert comprising only a single cutting edge, forexample, at least one channel extends from a clamping surface toproximate the cutting edge, and additional channels can be provided ifdesired.

FIGS. 1A-2D show a single sided cutting insert, however, it will beappreciated that the insert can be a double sided insert. FIGS. 1A and1C show a cutting tool and insert that is used in a turning operation,however, it will be appreciated that the cutting tool and insert can beused in any cutting operation.

In the present application, the use of terms such as “including” isopen-ended and is intended to have the same meaning as terms such as“comprising” and not preclude the presence of other structure, material,or acts. Similarly, though the use of terms such as “can” or “may” isintended to be open-ended and to reflect that structure, material, oracts are not necessary, the failure to use such terms is not intended toreflect that structure, material, or acts are essential. To the extentthat structure, material, or acts are presently considered to beessential, they are identified as such.

While this invention has been illustrated and described in accordancewith a preferred embodiment, it is recognized that variations andchanges may be made therein without departing from the invention as setforth in the claims.

The disclosures in Swedish patent application No. 0950092-7, from whichthis application claims priority, are incorporated herein by reference.

What is claimed is:
 1. A cutting insert comprising a top surface, abottom surface, a clamping surface for abutting a clamp, a cutting edgecomprising a corner, a hole extending through the insert from the bottomsurface and forming at least part of the clamping surface, and a channelextending from a part of the hole more distant from the top surface thanthe clamping surface toward the corner and reaching a land surface at apoint inward of the cutting edge, the hole being circular except whereit is interrupted by the channel.
 2. A cutting insert comprising a topsurface, a bottom surface, a clamping surface for abutting a clamp, acutting edge, a hole extending through the insert from the bottomsurface and forming at least part of the clamping surface, the holecomprising a fast portion having a substantially constant diameter alongits length and a second portion having a diameter that changes over atleast part of its length, and a channel extending from a pan of the holemore distant from the top surface than the clamping surface and reachinga land surface at a point inward of the cutting edge, the hole beingcircular except where it is interrupted by the channel.
 3. The cuttinginsert as set forth in claim 2, wherein the second portion comprises asubstantially frustoconical portion.
 4. The cutting insert as set forthin claim 1, wherein the clamping surface comprises a substantiallysmooth surface interrupted by the channel.
 5. The cutting insert as setforth in claim wherein a first portion of the hole closest to the topsurface forms at least part of the clamping surface.
 6. A cutting insertcomprising a top surface, a bottom surface, a clamping surface forabutting a clamp, a cutting edge comprising a corner, a hole extendingthrough the insert from the bottom surface and forming at least part ofthe clamping surface, and a channel extending from the clamping surfacetoward the corner and reaching a land surface at a point inward of thecutting edge, wherein a depth of the channel relative to the top surfaceis greater at the clamping surface than proximate the cutting edge, thehole being circular except where it is interrupted by the channel. 7.The cutting insert as set forth in claim 6, wherein a depth of thechannel decreases toward the cutting edge so that the second end of thechannel merges into the top surface before the cutting edge.
 8. Thecutting insert as set forth in claim 1, wherein the insert compriseschipbreakers on opposite sides of the channel.
 9. The cutting insert asset forth in claim 1, wherein the insert comprises at least two cuttingedges and at least two channels, at least one channel of the at leasttwo channels extending from the clamping surface to proximate and inwardof a respective one of the cutting edges.
 10. A cutting tool comprisinga cutting insert comprising a top surface, a bottom surface, a clampingsurface, and a cutting edge comprising a corner, and a toolholdercomprising a toolholder body having a pocket for receiving the insert,and a clamp for contacting the clamping surface and clamping the insertin the pocket, wherein a hole extends through the insert from the bottomsurface and forms at least part of the clamping surface, and the insertcomprises a channel extending toward the corner from a part of the holemore distant from the top surface than the clamping surface and reachinga land surface at a point inward of the cutting edge and the toolholdercomprises a toolholder passage in the body in flow communication withthe hole in the insert, the hole being circular except where it isinterrupted by the channel.
 11. The cutting tool as set forth in claim10, wherein the clamp comprises a clamping arm having an arm clampingsurface for contacting the clamping surface.
 12. The cutting tool as setforth in claim 11, wherein a forward portion of the clamping armincludes a recess to facilitate fluid flow from the hole to the channel.13. The cutting tool as set forth in claim 11, wherein the channel is atleast partially disposed beneath the arm clamping surface.
 14. Thecutting tool as set forth in claim 10, wherein the toolholder comprisesa shim disposed in the pocket, the toolholder passage extending at leastin part through the shim.